Is Cmd+R such a hard to reach combination to warrant the precious keyboard real state Caps Lock occupies? Me, I double mine as both Ctrl and Esc by using the excellent xcape https://github.com/alols/xcape on linux, and KeyRemap4MacBook otherwise.

I actually find it more relevant on my mac than on my linux box, since Ctrl on the Mac is in a horrible position, and it opens up a whole world of new easy shortcuts that conflict with little else. Plus Ctrl-C and Ctrl-L (clear) on the terminal.